Rotary printing press



May 21, 1929.

R. GROSSKOPF ROTARY PRINTING PRESS Filed Jan. 7, 1928 Patented May 21, 1929.

RICHARD GROSSKOPF, OI DRESDEN, GERMANY.

ROTARY PRINTING rnnss.

Application filed January 7, 1928. Serial No. 245,175.

My invention relates to a rotary printing ress and is in its details set forth in the folibwing description and in the annexed drawings which show by way of example a cross section of a press according to my invention, taken vertically and at right angles to the cylinder'shafts.

1 is the cylinder bearing the zinc-plate, 2 the printing cylinder, 3 the rollers for transmitting the printing ink onto the zinc-plate and 4 the roller, which takes up the ink from a trough 5. The trough 5 is held by arms 6 from a shaft 7 and can be swung out, when the device is not working in order to allow the rollers 3 to be lifted away from thecylinder 1 into the position shown in dotted lines where it is held by a hook 27. Carried from the same shaft 7 by arms 13 is a roller 8 the position of which is commanded by a lever 9 with a sliding roll 10 from a cam 11 on'the cylinder shaft 12 causing the said roller to touch alternately the trough-roller 4 and roller 3 thus taking up printing ink from the former and transmitting it to the latter.

' y invention 'now has for its object to allowof intermittently rotating the roller 4 in such a way, that its rotary movements can be varied in size. Each time the said roller is turned about a certain angle it offers anew part of its circumference bearing fresh printing ink to the roller 8. In regulating the width of the angle of its rotary step therefore I can apply more orless printing colour to the zinc-plate according to the demands of the printing process.

My invention consists in using meansfor accomplishing this 'which are very simple in construction and neither interfere with the swinging-outmovement of the trough 5 nor with the oscillating one of the roller 8. This is an important feature for apparatus of the kind set forth, which are to be built in small sizes. Further the controlling means are arranged in such a way, as to allow of varying the size of the rotary step mentioned above without need of stopping the machine.

In accomplishing this I use sprocket wheels 14, one on the shaft of the roller 4 and one on the shaft 7, with a chain 15 running over both of them and in addition a toothed disc or transmitting rollers and the ratchet wheel 16 loose on shaft 7, but fastened to the sprocket wheel on said shaft, an arm 17, also loose on said shaft, carrying a pawl or click 18 engaging the teeth of the ratchet wheel or disk 16, so that by movin the arm 17 the disc is turned by the click an with it the sprocket wheels 14, which move 4. The arm 17 receives its oscillating movements through the intermediary of an arm 19 from a doubled armed lever 20 journalled at 21 upon the machine frame 28. The lower short arm of this lever is commanded by a cam member 22 on the commanding shaft 12 whilst the upper long arm is slotted to receive in its slot 23 the end portion of arm 19, which can be clamped to the lever 20 by means of a hand screw 24 in any position along the slot 23 and will naturally impart a greater movement to arm 17 the further it is fastened towards the outer end of the slot 23. A causes the free back stroke of the motion.

The lever 20 being situated near one upright of the machine frame and the hand screw 24 being placed on the outward side on the said lever, it to displace the said screw during the operation of the machine and thereby to control the feed of printing colour to the zinc-plate whilst the machine is doing its Work.

The driving gears on the main shaft 26 are not shown. I

I claim:

In a rotary printing press, the combination, with a printing cylinder, a series of rollers for transmitting ink thereto, an intermittently rotatable ink take-up roller, a transfer roller oscillating between one of the aforesaid take-up roller, an ink trough in which said take-up roller is mounted on an axis-so as to be out of its working position, an oscillating actuating lever, an arm'pivotally and adjustably coupled to said lever, intermittent motion mechanism actuated by said arm and including a member loose on the axis around which the ink-trough is to be swung out, and a sprocket drive connection between said memher and the take-up roller.

RICHARD GROSSKOPE.

spring 25 oscillating the roller is evident, that one is able 

